The analysis of bone marrow is an invaluable tool for diagnosing a variety of hematologic and nonhematologic disease processes. Bone marrow is the soft material that fills the cavities of the bones. A bone marrow biopsy is performed to obtain a bone marrow sample for analysis. The bone marrow biopsy is a common, relatively simple procedure. Generally, the biopsy procedure is performed under local anesthesia, with the bone marrow sample obtained from the posterior superior iliac spine. In order to be diagnostically useful, the sample should be of adequate size with little or no distortion of structure. Moreover, a marrow sample should be easily obtained with minimal discomfort or risk to the patient. More specifically, following adequate local anesthesia of the periosteum, the biopsy needle with the stylet locked in place is advanced into the bone cortex and cavity (posterior iliac crest). Once the cortex of the bone is penetrated, the stylet is then removed. The aspirate (fluid from the marrow cavity) is drawn into a syringe and slides are quickly made from the aspirate. The biopsy needle is then slowly and gently advanced with smooth clockwise-counterclockwise motions until an adequate bone marrow sample is obtained. The biopsy needle is then rotated completely several times along its long axis and slowly removed with alternating rotary motions. This is done to break the sample off from the bone so that when the needle is withdrawn, the sample is retained in the bore of the needle. Once the needle is withdrawn, the bone marrow sample is gently removed with a long probe introduced through the distal cutting tip of the biopsy needle. The bone marrow sample can be expelled through the proximal portion of the biopsy needle and then appropriately analyzed.
In recognition of biopsy requirements, many instruments have been devised in order to sample bone marrow. Unfortunately, most of them do not consistently obtain an adequate sample with little or no distortion of structure. The Jamshidi biopsy needle device (Jamshidi and Swaim, J. Lab. Clin. Med., February 1971), for example, has been widely used but suffers from several deficiencies. That biopsy needle device generally includes a generally cylindrical cannula with a tapered distal portion including a sharp cutting Lip. The interior diameter of the distal portion is also tapered radially toward the cutting tip. A proximal end includes a coupling including a pair of finger grips, the coupling threadably engaging with a cap that locks over a knob of a stylet designed to interlock to fit the core. The stylet projects approximately 1 to 2 mm. beyond the cutting tip to protect a cutting edge and provide a means of entering the marrow. The Jamshidi device also accommodates a syringe with a catheter (tapered) tip. Unfortunately, a substantial portion of the sample may be lost during removal of the Jamshidi biopsy needle because the sample slides out of the needle necessitating repeated attempts to obtain an adequate sample. Moreover, the discovery of and loss of the tissue sample after enduring the rather painful procedure is disturbing to most patients. Furthermore, it is frustrating for the doctor to "complete" the procedure only to find the tissue sample lost after removal of the needle from the patient's body. In addition, the use of the Jamshidi needle (and other similar designs) require extensive rotary motion to be employed in an attempt to break the tissue sample off from the bone so it will be retained in the bore of the needle. This maneuver causes substantial and unnecessary pain and anxiety to patients.
Accordingly, there has been a need for a novel improved bone marrow biopsy needle that substantially prevents the loss of bone marrow sample and the method for using the same. There is a further need for a novel improved bone marrow biopsy needle and method that consistently obtain an adequate sample. There is a still further need for a novel improved bone marrow biopsy needle and method that permit obtaining a sample with little or no distortion of structure. There is an additional need for a novel improved bone marrow biopsy needle and method that allow bone marrow to be easily obtained, with minimal discomfort or risk to the patient. There is also a need for a novel improved bone marrow biopsy needle that will engage with a wide range of syringe types. The present invention fulfills these needs and provides other related advantages.